Lubricating oil



Patented Dec. 27, 1938 UNITED STATES LUBRICATING on.

Louis a Clarke, Fishkill, and Charles 0. Towno, Poughkeepsie,,N. Y., assignors' to The Texas Company, New York, N. Y., a corporation of llelaware No Drawing.- Application August 27, 1934,- S erial No. 741,724

3 Claims.

This invention relates to the manufacture of synthetic lubricating oils, and particularly to synthetic lubricating oils of improved character having an increased viscosity index, and to syn- 5 thetic oils applicable for blending with mineral lubricating oils to improve the character thereof. In the production of high grade lubricating oils, it is well known that a relatively small change in the viscosity of the oilbetween temperatures of say 100 F. and 210 -F., isidesirable. In other words, it is advantageous for the oil to have a relatively flat iscosity-temperature curve, which means that the oil has a high viscosity index as defined by Dean and Davis in their article in Chemical and Metallurgical Engineering, vol. 36, page, 618. Improvement in lubricating oils has heretofore been accomplished by refining, as by the use of selective solvents which are efiective in extracting or separating naphthenic constituents from paraflinic constituents, thereby producin a resulting raflinate of increased viscosity index.

This procedure involves expensive processing, and results in a reduced yield of finished oil.

The advantage of low pour point of a lubricating oil has long been recognized. Paraflin base and Mid-Continent lubricating oils have been subjected to dewaxing in order to reduce the pour Y point thereof. However, substantially complete removal of wax from suchoils results in a lower- 80 ing in viscosity index.

The present invention relates to the increase in viscosity index of naphthene base or paraffin base lubricating oils, which may or may not have been solvent refined as a primary step, by the ad 85 dition thereto of a material which is active to increase the viscosity index without objectionably affecting other desirable properties thereof. More particularly, the present invention relates to the production of an improved lubricating oil 40 of this type having increased viscosity index, by the addition thereto of a controlled proportion 01 a hydrogenated condensation product of an alkyl halide with an aromatic hydrocarbon. The invention also contemplates the preparation of synt6 thetic lubricating oils by hydrogenation of the condensation-product of an alkyl halide with an (or. av -9) the lower or normally gaseous oieflnes are particularly effective in this-reaction.

Of the aromatic hydrocarbons, benzene and its homologues, such for example as toluene, mesitylene, tertiary butylv benzene, tertiary amyl ben- 5 zene, normal butyl benzene, secondary butyl benzene, and the "like may be employed. Likewise, halogenated derivatives of benzene and its hom-' ologues, such as chlorbenzene," are satisfactory.

The condensation is eflected in the presence of 10 a catalyst of the Friedel-Craft type, such as anhydrous halides of aluminum, iron, boron, manganese, nickel, zinc, antimony, cadmium, tin-"and the like. Very satisfactory resultsare secured with anhydrous aluminum chloride. With proper .15

control of the proportions of the ingredients and the condensation reaction, a viscous synthetic lubricating oil may be produced. The condensation product may be allowed to stand and stratify into an upper oily layer and a lower sludge layer, 20

which are then separated by decantation. The. upper oily layer, is preferably distilled to remove lower boiling liquids including unreacted chemicals, to obtain as a residue a viscous synthetic oil of lubricating character. This oil is then hydro- 25 genated in accordance with well known hydrogenation practice, as by heating in the presence of hydrogen under pressure, and with or without a hydrogenation catalyst. A resulting synthetic oil of high viscosity index, which may be in excess of 100, is thereby obtained. .This oil itself is useful as a lubricating oil. Or, it may be blended with a petroleum lubricating oil in controlled proportions, to thereby increase the viscosity index of the petroleumlubricating oil. For example, proportions of from about 1% to 25% of the hydrogenated synthetic oil may be added to r a naphthene base or paramn base petroleum lubricating ofl to materially increase the viscosity index of the latter. However, the proportions of the blend may vary widely, and higher proportions of the synthetic oil up to about or more may be employed. But for economical reasons the lower percentages range mentioned is preferred. so

As a specific example or the present invention, the following is given:

1000 g. ethylene chloride 'were mixed with 1580 gxof benzene in the presence of 125 g. of anhydrous aluminum chloride. The mix was 50 warmed gently with agitation to about 36 C.,

when reaction set in which continued without further application of heat until a temperature of 45 C. was attained. Further heating ofv the mix to 0. caused additional reaction to set 66 The oil also had a high specific gravity of 1.03

and a low pour test of 25 F. When this oil is subjected to hydrogenation, by passing through a heating coil with hydrogen gas at a temperature'of around 600 F. and under a pressure of approximately 3000 lbs. per square inch, and

passed over a hydrogenation catalyst such as nickel, a further reaction occurs with the production of a more saturated oil of lubricating character having a still higher viscosity index, generally in excess of 100, and lower Conradson carbon. When the resulting hydrogenated oil is blended with a naphthene base oil, asin the proportion of about 25%, an increase in viscosity index of the order of about 30 -50 points is effected. Similarly, a blend of about 25% of this synthetic oil with a paraflln base petroleum lubricating oil results in an increase in viscosity index of the latter of about 2040 points.

A satisfactory product may also be prepared from the lower sludge layer. For example, a

green oil having a viscosity index in excess of 100 was obtained from the sludge layer in the example mentioned above. This oil had a specific gravity of 1.04, a Saybolt viscosity at 100 F. of

403 and at 210 F. of 60, and a pour test of 20 F. When this oil is subjected to hydrogenation in the manner specified above, a still higher viscosity index lubricatingoil is obtained which is very satisfactory for blending with a petroleum lubricating oil in the manner described above.

Obviously many modifications and variations of the invention, as hereinbefore set forth, may

thetic lubricating oil of high viscosity index and other desirable properties, which comprises condensing about five parts by weight of ethylene chloride with about eight parts by weight of benzene in the presence of a Friedel-Craft catalyst of the character of anhydrous aluminum chloride to produce an oily condensation product, separating the oily condensation product from sludge and removing lower boiling constituents therefrom to obtain a synthetic oil within the lubricating oil: boiling range having a viscosity index of about 80 or above, and then hydrogenating the obtained oily productqwithin the lubricating oil boiling range to produce a synthetic lubricating oil having a viscosity index in excess of 100.

2. The method in the manufacture of a. synthetic lubricating oil of high viscosity index and other desirable properties, which comprises condensing about five parts by weight of ethylene chloride with about eight parts by weight of benzene in the presence of a Friedel-Craft catalyst of the type of anhydrous aluminum chloride to produce an oily condensation product, allowing the, condensation product to stand to-stratify into an 'upper oily layer :and a lower sludge layer, separating the layers, removing lower boiling liquids from the upper layer to obtain a residue of a viscous oil within the lubricating oil boiling range having a viscosity index 9f about 80 or over, and then hydrogenating the 'viscous oil so obtained to produce a ,synthetic lubricating oil having a viscosity index of over 100.

3. The method in the manufacture of a synthetic lubricating oil of highviscosity indexand other desirable properties, which comprises condensing about five parts of ethylene chloride with abouteight parts of benzene in the presence of a Friedel-Craft catalyst of the character of anhydrous aluminum chloride. to produce an oily condensation product, allowing the condensation product to stand to stratify into an upper oily layer and a lower sludge layer, separating the layers, recovering a viscous oil within the lubrieating oil boiling range from the lower sludge layer having a viscosity index in excess of about 100, and then hydrogenating the recovered viscous oil to produce a synthetic lubricating oil having a viscosity. index substantially in excess of 100.

LOUIS A. CLARKE. CHARLES C. TOWNE. 

